US 11,807,594 B2
Process for the preparation of ethylene glycol
Eugene Marie Godfried Andre Van Kruchten, Amsterdam (NL); and Petrus Johannes Gerardus Boons, Singapore (SG)
Assigned to SHELL USA, INC., Houston, TX (US)
Appl. No. 17/311,871
Filed by SHELL OIL COMPANY, Houston, TX (US)
PCT Filed Dec. 6, 2019, PCT No. PCT/EP2019/083948
§ 371(c)(1), (2) Date Jun. 8, 2021,
PCT Pub. No. WO2020/120305, PCT Pub. Date Jun. 18, 2020.
Claims priority of application No. 18211334 (EP), filed on Dec. 10, 2018.
Prior Publication US 2022/0024841 A1, Jan. 27, 2022
Int. Cl. C07C 29/12 (2006.01); C07C 31/20 (2006.01); C07C 29/10 (2006.01); C07D 317/38 (2006.01); C07D 301/00 (2006.01)
CPC C07C 29/12 (2013.01) [C07C 29/106 (2013.01); C07C 31/202 (2013.01); C07D 317/38 (2013.01); C07D 301/00 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A process for the preparation of ethylene glycol from ethylene involves:
i) converting ethylene in the presence of oxygen, an epoxidation catalyst and a chloride 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 a catalyst and carbon dioxide in a carboxylation reactor to an ethylene carbonate stream;
iv) converting the ethylene carbonate stream in the presence of a catalyst in a hydrolysis reactor to an ethylene glycol stream and a carbon dioxide stream;
v) removing water from the ethylene glycol stream in a dehydration column to form a dehydrated ethylene glycol stream and a waste water stream;
vi) purifying the dehydrated ethylene glycol stream in a glycol distillation column to form a purified ethylene glycol product stream and a catalyst recycle stream;
wherein in step iii) and/or step iv) the catalyst is an iodide catalyst or a bromide catalyst;
the carbon dioxide stream resulting from step iv) comprises carbon dioxide, water, 2-chloroethanol and ethylene glycol and additionally comprises 2-iodoethanol or 2-bromoethanol and is condensed in a condenser to form a recycle carbon dioxide stream and a condensate stream; and
the carbon dioxide stream resulting from step iv), or the condensate stream, or the waste water stream resulting from step v) is contacted with an alkali metal containing basic compound to convert 2-iodoethanol or 2-bromoethanol into alkali metal iodide or alkali metal bromide and the resulting mixture comprising water, 2-chloroethanol and ethylene glycol and additionally comprising alkali metal iodide or alkali metal bromide is dehydrated.