Abstract:
The direct hydration process involves the catalytic addition of water to
ethylene. Phosphoric acid is commonly used as the catalyst. The reaction is
exothermic operating at about 3000C and 69 bar. Unconverted gases are
separated from ethanol in the ethano 1 scrubber and recyc 1ed to the reactor
feed stream. Oil ute aqueous ethanol (15 to 20 weight percent) is then fed
to the stripper where light by-products are removed. Stripper bottoms are
passed to the ethanol azeotrope tower where 190 proof ethanol products are
removed and sent to storage facilities. Overall process yield to ethanol is
about 98.5 mol percent.