METHOD OF PREPARING ISOPROPYL ALCOHOL Russian patent published in 1999 - IPC

FIELD: production of acetone, isopropyl acetate, and drugs. SUBSTANCE: method of preparing isopropyl alcohol by sulfuric acid hydration of propylene comprises absorption of propylene with 65-75 wt % sulfuric acid, hydrolysis of absorbate by addition of water and two-step separation of hydrolysate in stripping columns followed by neutralization and rectification of crude alcohol. Hydrolysis of absorbate is carried out by mixing it with water in ratio of 4-5 moles of water per 1 mole of sulfuric acid contained therein. Hyrolysate is admitted into first stripping column with temperature by 5-20 C lower than column temperature, and separation of hydrolysate is carried out in first stripping column at pressure of 0.3-1.0 atm and still temperature of 95-130 C, and column top temperature of 55-80 C so that fraction of distilled product is 0.3- 0.4 with respect to original hydrolysate, and sulfuric acid concentration in bottom product is 50-55 wt %, and acid is further made stronger to 65-75 wt % in second stripping column at pressure of 0.5-1.0 atm with stronger acid recycled to propylene absorption stage and with distillate recycled to hydrolysate preparation stage. Method makes it possible to reduce power consumption and to retain high quality of isopropyl alcohol. EFFECT: more efficient preparation method. 2 ex, 2 tbl