| 摘要 |
FIELD: industrial organic synthesis. SUBSTANCE: invention relates to improved method for production of sec-butyl acetate suitable as solvent for varnishes and paints and as precursor of sec- butyl alcohol. Sec-butyl acetate is prepared by alkylation of acetic acid with n-butenes, passing for that aim liquid butane-butene fraction in countercurrent mode through fixed catalyst bed, in particular through sulfocationite resin in H-form, after which unreacted butane-butene fraction is removed from reaction mixture by rectification and then recycled into alkylation reactor. Remaining sec-butyl acetate/acetic acid mixture is rectified in azeotrope rectification column using water as azeotropic reagent to produce sec-butyl acetate/water azeotrope as head fraction and to discharge anhydrous acetic acid from the bottom of column, which is transferred into alkylation reactor having been preliminarily purified by distillation and absorbing butane-butene fraction until molar ratio of acetic acid to butane-butene fraction achieves value from 2:1 to 10: 1. Heat provided by distilled acetic acid condensation is used for heating raw material fed into alkylation reactor. Water is fed into top of azeotrope rectification column in amounts required to maintain control plate temperature within the limits 112 and 122 C, said control plate being disposed in distillation section below water-containing stripping zone. Distillate flow is condensed and separated into water and organic (sec-butyl acetate) phases in phase separator, the water phase being used as reflux of azeotrope rectification column. The still of this column receives heat in proportion of amount of fed raw material, weight ratio of steam to raw material being 0.439- 0.546 kg/kg according to pressure gradient in column. EFFECT: improved quality of desired product, prolonged activity of sulfocationite resin, and reduced volume of waste waters. 4 cl, 2 dwg, 8 tbl, 39 ex |
