Process and apparatus for the preparation of alkylene glycol

A process for the preparation of an alkylene glycol from an alkene comprising:

• (a) supplying a gas composition comprising alkylene oxide, alkene, oxygen, carbon dioxide and water vapour to the bottom of an alkylene oxide absorber that comprises a column of vertically stacked trays, wherein each of the vertically stacked trays comprises:
• a perforated gas-liquid contacting member or members,
• a liquid inlet area,
• an outlet weir extending vertically above a surface of the tray at an opposite end of the tray from the liquid inlet area and having a height of at least 200 mm and at most 1500 mm, and
• a downcomer element which, in cooperation with an inner surface of a wall of the column, forms a downcomer for the passage of liquid downwardly to the liquid inlet area of an adjacent vertically stacked tray below, and
• allowing the gas composition to pass upwards through the alkylene oxide absorber;
• (b) supplying lean absorbent to the top of the alkylene oxide absorber and allowing the lean absorbent to pass downwards through the alkylene oxide absorber;
• (c) intimately contacting the gas composition with lean absorbent on the trays in the alkylene oxide absorber in the presence of one or more catalysts that promote carboxylation and hydrolysis;
• and
• (d) withdrawing fat absorbent from the alkylene oxide absorber.