Process for the hydration of olefins to alcohols

Process for the hydration of propylene in the presence of phosphoric acid-containing supported catalysts to isopropanol which comprises:

• a. carrying out the hydration in the vapor phase under conditions wherein the molar ratio of water to propylene is in the range of about 0.1 to 0.2 :
• 1, the reaction temperatures are in the range formation about 140.degree.-170.degree.C and the reaction pressure is in the range of about 20-45 atmospheres gauge thereby forming a reaction product mixture containing unreacted propylene, steam-volatile by-products and is opropanol;
• b. separating unreacted gaseous propylene from the reaction product mixture from (a);
• c. feeding the reaction product mixture from (b) to a washing extraction zone wherein said by-products are separated from said isopropanol using 50 to 150 kg of steam per 100 liters of pure isopropanol to vaporize said by-products which are removed overhead, said isopropanol, free of said by-products, being withdrawn from the sump of said washing zone;
• and
• d. thereafter condensing the steam and by-products withdrawn overhead from the washing zone in step (c) and recycling same to the hydration step thereby supplying the water required for the hydration and increasing the concentration of the by-products which prevents further formation of by-products in the hydration.