METHOD OF RECOVERY OF ORGANIC SOLVENTS FROM AIR-VAPOR MIXTURE Russian patent published in 1995 - IPC

FIELD: chemical industry. SUBSTANCE: air-vapor mixture with organic solvents is in series passing through layer of recovery active carbon with size of granule of 2-5 mm and loose density of 570-580 g/dm³, through net of filtering fibre-glass fabric and layer of adsorbent of activated carbon fibre with micropores diameter of and with its resistance to air stream of no more than 20 mm of water column and ratio of volumes of layers of adsorbent of activated carbon fibre and recovering active carbon as 1:(10-12). Method provides also for solvents desorption by live steam, condensation of formed air-vapor mixture, separation of condensate on layer of solvent and layer of water phase and rectification of water phase with following condensation. In the case, air-vapor mixture, that has 2-5 g/m³ of dichloroethane and 80-300 mg/m³ of ethyl alcohol, is subjected to passing through recovery active carbon under temperature of 20-30 C until concentration of dichloroethane at exit from layer is 200-500 mg/m³. Passing through layer of adsorbent of activated carbon fibre is exercised until concentration of dichloroethane at exit of the layer is 1,0 mg/m³. Desorption is exercised by steam with temperature of 102-110 C and initial pressure of 0.11-0.12 MPa during 1.0-1.2 h. Then layers are subjected to drying within 1 - 1.2 h by air-vapor mixture, coming out from layer of adsorbent of activated carbon fibre with concentration of dichloroethane of 1 mg/dm³ after hearing up to 60-85 C. Condensation of air-vapor mixture, formed after desorption, is exercised by cooling to + 1 C. Separation of condensate is exercised within 2 h. EFFECT: method allows to increase recovery of solvents from air-vapor mixture. 4 cl, 1 dwg, 1 tbl