Patent ID: 8741252
Filing Date: 2014-06-03
Classification: C01B

Abstract:
1. A process for producing an aerogel, comprising: (a) placing a wet gel comprising a first solvent into a porous material treatment section of an apparatus, (b) feeding both a supercritical second solvent and a third solvent to a high-pressure mixing section of said apparatus, (c) mixing the third solvent and the supercritical second solvent in said high-pressure mixing section of said apparatus to form a mixed solvent; (d) discharging the mixed solvent from said high-pressure mixing section of said apparatus and feeding the mixed solvent into the porous material treatment section of said apparatus, thereby feeding the mixed solvent into the wet material, such that at least some of the first solvent in the wet gel is removed and replaced with at least some of the mixed solvent, (e) discharging the resulting solvent from said high-pressure mixing section of said apparatus, (f) continuously recirculating said resulting solvent into said high-pressure mixing section of said apparatus; and, (g) adding additional supercritical second solvent to said high-pressure mixing section so that the additional supercritical second solvent increases the concentration of supercritical second solvent in the continuously recirculating resulting solvent, so the mixing percentage of the second solvent continuously increases with the lapse of time during feeding.