Process for the preparation of ethylene glycol

A process for the production of ethylene glycol from ethylene, said process comprising the steps of:

• i) converting ethylene in the presence of oxygen, an epoxidation catalyst and a moderator to ethylene oxide in an ethylene oxide reactor;
• ii) absorbing the ethylene oxide in an aqueous absorbent and then stripping said absorbent to provide an aqueous ethylene oxide stream;
• iii) converting the aqueous ethylene oxide stream in the presence of one or more catalysts and carbon dioxide to an ethylene carbonate stream in one or more carboxylation reactors;
• iv) converting the ethylene carbonate stream in the presence of one or more catalysts to a first ethylene glycol stream in one or more hydrolysis reactors;
• v) removing water from the first ethylene glycol stream to form a dehydrated ethylene glycol stream and a waste water stream in one or more dehydration columns;
• vi) purifying the dehydrated ethylene glycol stream in one or more glycol distillation columns to form a purified ethylene glycol product stream and a catalyst recycle stream;
• wherein the first ethylene glycol stream comprises inorganic chloride contaminants and wherein the process comprises the additional steps of vii) converting the inorganic chloride contaminants to 2-chloroethanol by reaction with ethylene oxide in the one or more dehydration columns;
• and
• viii) removing 2-chloroethanol in the waste water stream.